Metrics

Page-level Metrics

These are the top-level measurements captured and displayed for the overall page.

Load Time

The Load Time is measured as the time from the start of the initial navigation until the beginning of the window load event (onload).

Fully Loaded

The Fully Loaded time is measured as the time from the start of the initial navigation until there was 2 seconds of no network activity after Document Complete. This will usually include any activity that is triggered by javascript after the main page loads.

First Byte

The First Byte time (often abbreviated as TTFB) is measured as the time from the start of the initial navigation until the first byte of the base page is received by the browser (after following redirects).

Start Render

The Start Render time is measured as the time from the start of the initial navigation until the first non-white content is painted to the browser display.

Speed Index

The Speed Index is a calculated metric that represents how quickly the page rendered the user-visible content (lower is better). More information on how it is calculated is available here: Speed Index

DOM Elements

The DOM Elements metric is the count of the DOM elements on the tested page as measured at the end of the test.